Calculation of mold cavity size: (1) Determination of the radial size of the mold cavity: Calculated based on the average value, the average shrinkage S of the plastic part is 0.6%. The maximum wear amount of the 7-level precision mold is taken from the plastic part. 1/6 of the tolerance; the mold manufacturing tolerance ￡z=△/3 takes x=0.75. LM1 5.98O+0.48 →6.26O-0.48 (LM1)o+￡z=〔（1+s）Ls1-X△〕o+￡z =〔（1+0.006）×0.26-0.75×0.48〕0.18 =5.930 +0.16 ②LM2 48O+0.48 →5.28O-0.48 (LM2) o+￡z=〔(1+S) ×5.28-0.75×0.48〕o+￡z =4.950.16 ③LM3 5.15O+0.48 →5.63O-0.48 (LM3 ) o+￡z=〔(1+S) ×5.63-0.75×0.48〕o+￡z =5.300.16 ④LM4 1O+0.48 →1.38O-0.38 (LM4) o+￡z=〔(1+S) ×1.38- 0.75×0.38〕o+￡z =1.100.12 ⑤LM5 18.89O+0.88→19.77O-0.88 (LM5)o+￡z=〔(1+S) ×19.77-0.75×0.88〕o+￡z =19.230.29 ⑥LM6 0.96 O+0.38→1.34O-0.38 (LM6)o+￡z=〔(1+S) ×1.34-0.75×0.38〕o+￡z =1.060.12 ⑦LM7 ∮2O+0.38 →∮2.38O-0.38 (LM7)o+ ￡z=〔(1+S) ×2.38-0.75×0.38〕o+￡z =2.100.12 ⑧LM8 ∮6.1O+0.58 →∮6.68O-0.38 (LM7)o+￡z=〔(1+S) ×6.68 -0.75×0.38〕o+￡z =6.290.19 ⑨LM9 ∮0.77→1.05 (LM9) =〔(1+S)*1.05-0.75*0.38〕 =0.86 o+0.13 ⑩LM10 10.5 →11.18 (LM10) =〔(1 +S)*11.18-0.75*0.68〕 =10.74 (2), Core height dimension ① H 4.7 →5.18 HM1 =〔(1+S)*5.18-0.75*0.48] =〔(1+0.006)*4.7+ 0.5*0.48] =4.97 ② H 8.9 →9.48 HM2 =〔(1+S)*9.48-0.75*0.58〕 =[(1+0.006)*8.9+0.5*0.58] = 9.25 (3), core diameter Directional size: ① LM1=5.98 →5.98 LM1 =［（1+s）*Ls+x△］ =［（1+0.006）*5.98+0.75*0.48］ = 6.37 ② LM2=2.12 →2.12 LM2 =［（1 +s) * Ls + x 〕 =〔(1+0.006)*1.15-0.5*0.38〕 =0.97 Hm2 10.5 →11.18 Hm1 =〔(1+s)Hs2-x 〕 =〔(1+0.006)*11.18-0.5*0.68〕 =10.9 (5) Design and calculation of the core-pulling mechanism on the side of the inclined guide column ①: Core-pulling distance (S) S=S1+(2→3)㎜ = +(2→3)㎜ = +(2→3)㎜ =2.93+ 2.5㎜ =5.43㎜ ②: Core pulling force (Fc) Fc=chp( cos -sin ) = [2*3.14*(3.1+1)∕2*10 ]*3.5*10 *1*10 *(0.15*cos30 -sin30 ) =60.38N ③: The inclination angle of the inclined guide column ( ) The inclination angle of the inclined guide column is one of the main technical data of the side centering mechanism. It is directly related to whether the plastic part can be taken out smoothly after molding, as well as the pushing force and pushing distance. .

For the sake of safety, this mold chooses =22 30 frustum bevel angle ( ) =25 mold opening distance corresponding to the core pulling distance H=s*cot =5.43*cot 22.5 =2.414㎜demoulding force (Ft) Ft=Fc= 63.08N Bending force (Fw) Fw=Ft∕cos =63.08∕cos22.5 =68.57N Mold opening force (Fk) Fk=Ft*tan =63.08*tan22.5 =26.13N ④: Calculation of the working length of the inclined guide column ( L) L=S*(cos ∕sin ) =5.43*cos22.5 ∕sin22.5 =29.5㎜ Six mold related parameter verification (1) Determination and verification of mold closing height 1. Determination of mold closing height. According to the size of each template of the standard mold base and other dimensions of the mold design: Fixed mold base plate H = 16mm 2. Fixed mold plate H = 18mm Moving mold plate H = 23mm Support plate H = 15mm Pad? H pad = 40mm Moving mold Seat plate H moving = 16mm Mold closing height: H closed = H fixed + H + H. + H support + H pad + H moving = 16 + 18 + 23 + 15 + 40 + 16 = 128mm Check the mold installation part The overall dimensions of the mold are 160mm × 100mm, and the maximum installation size of the XS-ZS-22 injection machine template is 250 × 350, so it can meet the mold installation requirements. Since the minimum thickness of the mold allowed by the XS-ZS-22 injection machine is 60mm and the maximum thickness is 180mm, it meets the mold installation requirements. Mold opening stroke check: Since the plastic part is small and the centering distance is small, it meets the requirements. (The maximum mold opening and closing stroke of this injection machine is 160mm) 7. Selection of mold materials and determination of heat treatment. The structure of the plastic injection mold is relatively complex. A set of molds has various parts. The position of each part in the mold, Different functions have different performance requirements for materials. Therefore, choosing high-quality and reasonable materials is the guarantee for producing high-quality molds. The requirements for materials used in plastic molds are: good machining performance; sufficient surface hardness and wear resistance; sufficient strength and toughness; good polishability; good heat treatability; good heat treatability ; Has good corrosion resistance and surface processability. Here we check the manual and get the following table: Mold parts use requirements Mold material heat treatment instructions The formed parts have high strength, good wear resistance, small heat treatment deformation, and sometimes require corrosion resistance 5GrMnMo, 5GrNiMo, 3GrW8V quenching, medium temperature tempering ≥46HRC Suitable for molds with high molding temperature and high molding pressure T8, T8A T10 T10A T12 Quenching and low temperature tempering ≥55HRC Used for molds with simple product shape and small size 38GrMoAlA Modulated nitriding ≥55HRC Used for high wear resistance requirements and ability to prevent heat Interlocking movable molded parts 45, 50, 55, 40Gr, 42GrMo Modulation, surface quenching ≥55HRC Thermoplastic molding molds for mass production of products 10, 15, 20, 12GrNi2 Carburizing, quenching ≥55HRC Easy to cut or use plastic processing Method for making small molds. Beryllium copper has excellent thermal conductivity and good wear resistance. It can be cast and formed into zinc-based alloys and aluminum alloys. It is used for product trial production or formed parts in small and medium-sized batch production. Ductile iron is normalized or annealed and normalized ≥200HBS. Used for large molds. The main flow bushing has good wear resistance and sometimes requires corrosion resistance 40, 50, 55. Surface quenching ≥55HRC. Push rod, pull rod, etc. have certain strength and wear resistance. T8A T8 T10. Quenching, low temperature tempering ≥55HRC. Guide pillar, guide The surface of the sleeve is wear-resistant, tough, resistant to bending and not easy to break. 20. 20Mn2B Carburizing and quenching ≥55HRC T8A\T10A Surface quenching ≥55HRC 45 Modulation, surface quenching and low-temperature tempering ≥55HRC Brass H62\bronze alloy is used for guide sleeve forming Parts with high strength, good wear resistance, small heat treatment deformation 9Mn2V Quenching and low temperature tempering ≥55HRC Used for molds with large production batches and high strength and wear resistance requirements Gr12MoV Quenching and medium temperature tempering ≥55HRC Same as above, but with small heat treatment deformation, Good polishability Various templates, push plates, fixed plates, mold bases, etc. Certain strength and stiffness 45, 50, 40Gr Modulation ≥ 200 HBS Structural steel Q235 Ductile iron used for large molds HT200 only used for mold bases Eight main parts of injection molds Processing requirements and process preparation 8.1 Processing requirements for the main parts of the injection mold 8.1.1 Technical requirements for blank forging In order to save raw materials and processing hours and improve production efficiency, the mold blank is free forged. At the same time, the material structure is made fine and carbonized through forging The material distribution and streamline distribution are reasonable, thereby improving the heat treatment performance and extending the service life of the mold. In addition, in order to ensure the hardness of forging, eliminate forging stress, and soften the forging to facilitate subsequent mechanical processing, the blank should also be modulated (quenched + high temperature tempering) after the forging is formed.

8.1.2 Plane processing Plane processing is the processing of the end faces and sides of each part in the mold. The machining process is divided into rough machining, semi-finishing and finishing. Since this mold is a small mold, planing or milling can be used for rough processing, and fine milling or fine grinding can be used for finishing on the left rear. 8.1.3 Cavity processing Cavity processing methods can be divided into three types according to processing conditions and process methods: general machine tool cavity processing (turning, milling, planing, grinding, drilling). Special machine tool processing (copying milling, CNC machine tools, machining centers, etc.). This plastic part requires high surface quality, but the cavity of the part is not very complicated. General machine tools and CNC machine tools can process the cavity.

Considering the above situation, this mold cavity can be CNC milled as the main processing method, and Cimatron E is used for programming post-processing